package cn.edu.scau.cmi.liujiaming.chapter05;

public class ChildLader extends Lader {
	double bottom;
	ChildLader(double above,double bottom,double height){
		this.above=above;
		this.bottom=bottom;
		this.height=height;
	}
	double getArea() {
		return (above+bottom)*height/2;
	}

}
